This invention relates to a fuel supply device of a two-cycle engine for an outboard motor and more particularly to an improved, compact and efficient fuel system for a two-cycle engine.
Two-cycle engines have, as one of their principal advantages, extreme simplicity. Because of this, two-cycle engines enjoy a wide variety of applications, for example, in outboard motors. With a crankcase compression two-cycle engine, it is the normal practice to draw a fuel/air mixture into the crankcase for compression. The compressed mixture is then transferred to the combustion chamber through one or more transfer ports where it is fired. The rather lengthy path through which the fuel/air mixture must pass gives rise to some difficulties, particularly when low quality fuels such as kerosene are employed. When using such fuels, there is a likelihood of condensation of the fuel before it reaches the combustion chamber. This is particularly true under such conditions as starting and during acceleration. The condensation can cause a weaker than desired mixture which can make running conditions either unsatisfactory or, in extreme cases, impossible.
It is, therefore, a principal object of this invention to provide an improved fuel supply system for a two-cycle internal combustion engine.
It is another object of this invention to provide an improved fuel supply system for a two-cycle crankcase compression internal combustion engine wherein the likelihood of condensation is reduced, thus rendering the engine more adaptable for running with low quality fuels.
As has been noted, their simplicity makes two-cycle engines very desirable for use as the power unit of an outboard motor. In such an application, the engine is disposed so that its output shaft rotates about a generally vertically extending axis. This results in cylinders that are horizontally disposed. Normally, it has been the practice to induct the fuel/air mixture into the crankcases from generally horizontally disposed carburetors. As has been discussed above, however, the crankcase induction causes the likelihood of fuel condensation, particularly when low quality fuels are employed. However, other alternative locations for introduction of the fuel have been rather difficult due to the extremely compact nature of the outboard motor and its surrounding protective cowling.
It is, therefore, a principal object of a further feature of this invention to provide an improved, compact, high efficiency induction system for a two-cycle internal combustion engine.
It is a further object of this invention to provide am improved layout and arrangement for introducing fuel into the two-cycle engine of an outboard motor.